Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02689041 2009-12-23
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Separation Apparatus
The present invention relates to separation apparatus and to methods for
separating
materials.
Separation apparatus are used in the recycling industry to separate mixtures
of
materials for separate processing. Examples of such mixtures include: a
mixture of glass
fragments mixed together with particles of shredded paper; shredded or news
paper mixed
together with heavy plastics such as food containers and bottles; and metal
cans mixed
together with plastics and other materials.
Known separation apparatus use an air moving device such as a fan or blower to
separate the mixture of materials into like fragments. However, with said
known separation
apparatus, materials displaced can come into contact and become tangled in a
rotating
element of the fan or blower thereby rendering the separation apparatus
inoperable.
According to the present invention there is provided a separation apparatus
and method
of separating materials as set forth in the appended claims. Other features of
the invention will
be apparent from the dependent claims, and the description which follows.
According to the present invention in a first aspect there is provided a
separation
apparatus. The separation apparatus may comprise a material separator
positioned above a
conveyor. The conveyor may be arranged to convey a mixture of materials to the
material
separator for separation. The material separator may comprise a suction duct
comprising a
sidewall. The sidewall may define a passageway linking an inlet positioned
adjacent the
conveyor to an outlet positioned away from the conveyor. The material
separator may
comprise an airflow generator arranged to blow air through a slit in the
sidewall into the
passageway at a position between the inlet and the outlet. In use, the airflow
generator may
blow air through the slit in a direction which is towards the outlet. Blowing
air towards the
outlet may create a pressure difference between the inlet and the outlet to
generate an airflow
caused by air being sucked into the inlet. The sucking of air into the inlet
may cause the
relatively low density materials to be lifted from the conveyor and sucked
into the passageway
from the mixture of materials leaving relatively high density materials on the
conveyor.
According to the present invention in a second aspect there is provided a
material
separator for use in a separation apparatus, such as the separation apparatus
of the first
aspect. The material separator may comprise a suction duct comprising a
sidewall which
defines a passageway linking an inlet positioned to an outlet. The material
separator may also
have an airflow generator arranged to blow air through a slit in the sidewall
into the
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passageway at a position between the inlet and the outlet. In use, the airflow
generator may
blow air through the slit in a direction which is towards the outlet for
creating a pressure
difference between the inlet and the outlet to generate an airflow from the
inlet to the outlet
which creates a suction effect at the inlet.
The pressure difference may create an even airflow between the inlet and the
outlet.
The suction effect caused by the airflow may be at its strongest along the
sidewall. The ability
to create a suction effect by air through the sidewall into the passageway at
a positioned
spaced apart from the inlet may minimise the amount of displaced material that
may come into
contact with a blower or fan of the airflow generator.
Suitably, the airflow generator is arranged to blow air in a direction which
is
perpendicular to the conveyor for generating an airflow that is perpendicular
to the conveyor.
Suitably, the airflow generator comprises a supply fan for blowing air through
the slit.
Suitably, the airflow generator comprises an air collection chamber in fluid
communication with
the supply fan and the slit. Suitably, in use, the supply fan blows air into
the air collection
chamber where it is collected before being pushed through the slit. Suitably,
the air is pushed
through the slit at high pressure. Suitably, an air entry point of the supply
fan into the air
collection chamber is spaced apart from the slit. Suitably, the air entry
point is on a wall of the
air collection chamber opposed to the wall on which the slit is located.
Suitably, a wall of the
air collection chamber is the sidewall of the suction duct.
Suitably, the sidewall is shaped to define a funnel shaped passageway; wherein
the inlet
is defined by the relatively narrow part of the funnel and the outlet is,
defined by the relatively
wide part of the funnel.
The funnel shaped passageway may create an aerofoil effect which cause the
airflow to
be even or laminar.
Suitably, the slit runs circumferentially around the sidewall. Suitably, the
slit runs around
the sidewall in a direction which is parallel to the conveyor.
Suitably, the slit is positioned at a point between a first section of the
sidewall and a
second section of the sidewall. Suitably, in the first section, the sidewall
is dimensioned to
define a passageway comprising a smaller width than the second section.
Suitably, in the
second section, the width of the sidewall is varied to define a passageway
that expands from
the gap (slit) to the outlet. Suitably, a top edge of the first section is
positioned adjacent a
bottom edge of the second section in a direction that is parallel to the
conveyor. Suitably, the
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top edge and bottom edge define the slit. In this way, the airflow from the
first section into the
second section is such that an air barrier may be defined over the slit to
minimise the likelihood
of the low density material entering into the slit and becoming entangled or
contacting the
means for blowing air of the airflow generator.
Suitably, the sidewall defines a passageway which is circular in cross-
section. Suitably,
the sidewall defines a passageway which is polygonal in cross-section.
Suitably, the sidewall defines a passageway in the first section which is
circular in cross-
section. Suitably, the sidewall defines a passageway in the first section
which is polygonal in
cross-section. Suitably, the sidewall defines a passageway in the second
section which is
circular in cross-section. Suitably, the sidewall defines a passageway in the
second section
which is polygonal in cross-section.
Suitably, the conveyor is a vibratory conveyor comprises a first level.
Suitably, the first
level comprises a first conveying member which is arranged along a bottom
surface extending
from a bottom edge of the sidewall. Suitably, the first conveying member
comprises an
operative end in which an edge is shaped and dimensioned to correspond to the
shape of the
inlet. Suitably, in use, the first conveying member is positioned such that
the generated air
flow causes the low density material to be sucked from the operative end into
the inlet leaving
the high density material to fall from the operative end. Suitably, the
operative end is
positioned beneath the inlet so that the edge of the operative end is aligned
with an edge of
the inlet.
Suitably, the first conveying member is annular in shape. The edge of the
operative end
may be an aperture shaped and dimensioned to correspond to the inlet.
Alternatively, the first
conveying member is rectangular in shape. An edge of the operative end may
comprise a first
region which- is shaped and dimensioned to correspond to the inlet and second
regions either
side of the first region, which are shaped to be angled away from the inlet.
Suitably, when the first conveying member is annular in shape, the first
conveying
member may comprise a wall and a floor. The wall may stand up from the floor
on an edge
opposed to the operative end.
Suitably, when the first conveying member is rectangular in shape, the first
level may
comprise a plurality of first conveying members. Suitably, the first conveying
member
comprises a wall and a floor. Suitably, the wall stands up from the floor
around the edges of
the first conveyor leaving a gap in the first region through which the high
density material falls
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from the first level, in use. The wall may define a chute-like conveyor
arranged to channel the
mixture of material to the operative end.
Suitably, the vibratory conveyor comprises a second level beneath the first
level relative
to the inlet. Suitably, the second level comprises a second conveying member
that comprises
an operative end that extends beyond the edge of the first conveying member
towards the
centre of the inlet. Suitably, an edge of the operative end is arced or
straight.
Suitably, a gap between the bottom surface of the suction duct and the first
level and a
gap between the first level and the second level define a first and second air
channel through
which air is drawn into the inlet. The air channels may create an even air
flow that lifts the low
density material from the high density material as the air is sucked towards
and into the inlet.
Suitably, a first and second sidewall is arranged to connect the first level
to the second
level to form a walled air channel through which air is blown, in use, to aid
the separation of
low density material from high density material.
Suitably, the conveyor is an endless conveyor. Suitably, the conveyor revolves
at a
predetermined speed. Suitably, the predetermined speed is selected to allow
the airflow to act
on the mixture of materials for a predetermined time to lift and separate the
low density
material from the high density material.
Suitably, the conveyor is a predetermined height from the inlet. The
predetermined
height may be selected to ensure that the strength of the airflow acting upon
the mixture of
materials is such that the low density materials are separated from the high
density materials.
The separation apparatus of any preceding claim in which a discharge duct is
connected
to the outlet to channel the low density material away from the material
separator to a first
collection point, whilst the high density materials are conveyed to a second
collection point.
According to a second aspect of the present invention there is provided a
method of
separating low density materials from high density material contained in a
mixture of materials.
The method may comprise the steps of: conveying a mixture of materials to an
operative point;
and generating at the operative point an airflow by blowing air through a slit
in a sidewall of a
duct into a passageway linking an inlet to an outlet. The air that is blown
through the slit in a
direction which is towards the outlet may create a pressure difference between
the inlet and
the outlet that may in turn generate an airflow at the operative point which
may cause the
relatively low density materials to be lifted and sucked into the inlet and
out through the outlet
whilst the relatively high density materials are conveyed away from the
operative point.
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The method may further comprise channelling the low density materials away
from the
suction duct into a first collection point and routing the high density
materials to a second
collection point.
5 For a better understanding of the invention, and to show how embodiments of
the same
may be carried into effect, reference will now be made, by way of example, to
the
accompanying diagrammatic drawings in which:
Figure 1 shows a sectional side view of an air moving device of an embodiment
of the
present invention;
Figure 2 shows a plan view of an air moving device of an embodiment of the
present
invention;
Figure 3 shows a plan view of a separation apparatus of an embodiment of the
present
invention;
Figure 4 shows a sectional side view of the separation apparatus of Figure 3;
Figure 5 shows a plan view the separation apparatus of another embodiment of
the
present invention showing a partial section at point A;
Figure 6 shows a sectional side view of a separation apparatus of the
embodiment
shown in Figure 5;
Figure 7 shows a perspective view of a vibratory conveyor for use with an air
moving
device of an embodiment of the present invention;
Figure 8 shows a sectional side view of a separation apparatus of a still
further
embodiment of the present invention;
Figure 9 shows a sectional front view of the separation apparatus of Figure 8;
and
Figure 10 shows a plan view of the separation apparatus of Figure 8.
Figures 1 - 10 show exemplary embodiments of a separation apparatus 1,2,3 of
the
present invention. The separation apparatus 1,2,3 comprises an air moving part
10 to which a
mixture of waste materials to be separated is conveyed. The air moving part 10
is a material
separator and features an airflow generator 11 and a suction duct 12. In use,
the airflow
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generator 11 creates an airflow in the suction duct 12 of sufficient velocity
to lift and suck low
density materials from the mixture of waste materials into the duct 12, whilst
the high density
materials are conveyed away from the suction duct 12.
Figure 1 shows the airflow generator 11 that comprises a supply fan 13 and an
air
collection chamber 14. The supply fan 13 is in fluid communication with the
air collection
chamber 14 and supplies air into the air collection chamber for subsequent
distribution to the
suction duct 12. The supply fan uses a 15kw blower to supply pressurised air
to the air
collection chamber 14.
It is of course possible for any type and power of supply to be used to blow
air into the
air collection chamber.
The air collection chamber 14 is an annular chamber which surrounds the
suction duct
12. That is, the walls of the air collection chamber are arranged to surround
the suction duct
12 and share a sidewall 15 with the suction duct. Pressurised air is supplied
from the air
collection chamber to the suction duct 12 through a slit 16 in the sidewall
15.
The slit 16 runs circumferentially around the sidewall 15 in a direction which
is parallel to
a bottom surface 12a of the suction duct 12. In the suction duct 12, the slit
16 is located in a
position between the inlet 17 and the outlet 18. For example, the slit is
located equidistant
between the inlet and the outlet. In other examples, the slit can be arranged
in any position
between the inlet and outlet.
The slit 16 is defined by a gap in the sidewall 15 between a first section and
a second
section of a passageway 19 defined by the sidewall 15. The sidewall 15 defines
a funnel-
shaped passageway 19. The first section runs from the inlet 17 to the slit 16
and the second
section runs from the slit 16 to the Qutlet 18. The first section is
cylindrical in shape and has
the same width or diameter along its length. The second section is conical in
shape and has a
varying width from the slit 16 to the outlet 18. The cone shaped second
section can be
arranged to expand at any angle relative to the sidewall of the first section.
For example, the
cone shape expands at an angle of 15 relative to the sidewall of the first
section.
The side wall of the example embodiment shown in Figure 1 defines a passageway
19
with a circular cross-section when viewed in plan. However, the sidewall can
be configured to
define a passageway of any shape or combination of shapes, for example,
elliptical, or
polygonal such as a quadrilateral, pentagonal, hexagonal, heptagonal and
octagonal.
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The sidewall is dimensioned such that the passageway 19 in the first section
is in the
region of 0.70m - 1.5m. For example, the width or diameter of the sidewall is
1.12m. The
sidewall is dimensioned such that the passageway 19 in the second section
expands from
0.75m at the slit 16 to 1.12m at the inlet 18. For example, the sidewall 15 is
dimensioned to
expand to define a passageway 19 with a width of 1.12m at the outlet 18.
Figure 2 shows that a top edge 19 of the first section, i.e. the edge opposed
to the inlet
17, is located in a region in which a bottom edge 20 of the second section,
i.e. the edge
opposed to the outlet 18, is also located. The top edge 19 and the bottom edge
20 are
displaced in a direction parallel to the bottom surface 12a by a predetermined
distance to
define the slit 16. The size of the slit 16 in the sidewall 15 is
predetermined to create the
desired pressure difference between an inlet 17 and an outlet 18 of the
suction duct 12. The
slit 16 could be in the range of 14 - 24 mm in width. For example, the slit 16
could be 19mm
in width.
In operation, the speed of the pressurised air flowing from the air collection
chamber 14
through the slit 16 is in the region of 75 - 95 metres per second. Figure 1
shows that due to
the shape and angle of the cone shaped second section, the pressurised air
follows the profile
of the cone like an aerofoil. This even or laminar airflow shown by the arrows
A creates a
pressure difference between the sidewall of the second section and a central
region of the
second section. That is, an area of low pressure is generated in the central
region. This area
of low pressure creates a vacuum-like effect, which sucks air in from a
relatively high pressure
area surrounding the inlet 17 and through the passageway 19 as shown by the
arrows B. This
sucked in air being discharged through the outlet 18.
In use, the airflow along the sidewall 15 also creates an air boundary that
covers the
slot. The airflow boundary acts to minimise the amount of light density
material that is able to
inadvertently pass through the slit into the air collection chamber 14.
Figure 3 shows a first embodiment of a separation apparatus 1 in which the
material
separator 10 described above is used to suck low density material in through
the inlet 17. In
use, a mixture of materials is conveyed to the inlet 17 with a vibratory
conveyor 21, which is
annular in shape. The vibratory conveyor 21 has a first end 23 which is fed
the mixture of
materials by a feed conveyor 24, and an opposed operative end 25 at which the
low density
materials are separated from the high density materials in the mixture.
Standing up from the
first end 23 is a wall that, in use, reduces the amount of material that may
otherwise
inadvertently fall from the first end 23.
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The mixture of materials can be of any type of materials. One such type is a
by-product
of common recycling facilities in which less dense particles are mixed up with
more dense
particles. For example, the mixture of materials can be of broken glass and
paper, such as
shredded or news paper; heavy plastics such as food containers and bottles,
and lighter
plastics or paper; Metal cans or plastics and other light fractions.
The vibratory conveyor 21 is positioned beneath the inlet 17 to run parallel
to the bottom
surface 12a. The vibratory conveyor 21 has two levels. Each level has a
conveying member
26, 27. A first conveying member 26 of the first level is spaced apart from
the bottom surface
12a. A second conveying member 27 of the second level is spaced apart from the
first
conveying member 26.
The size of gap between the bottom surface 12a and a floor 28 of the first
conveying is
predetermined according to the type of materials to be separated. The size of
the gap is in the
range of 50mm to 150mm. For example, to separate a mixture of glass and paper
the gap is
100mm when the air flow speed from the inlet 17 to the outlet 18 is, for
example, 85 metres
per second.
The size of the gap between the floor 28 of the first conveying member 26 and
the floor
29 of the second conveying member is between 100mm to 200mm, for example
150mm.
The conveying members 26, 27 each have an operative end, which define an
aperture
through the conveying members 26, 27. The first conveying member 26 has an
operative end
25a shaped and dimensioned to define an aperture that corresponds to the inlet
17. The
second conveying member has an operative end 25b which is shaped to correspond
to the
inlet, but is dimensioned so that, when viewed in plan, the second conveying
member extends
beyond the operative end 25a of the first conveying member. That is, the
aperture defined in
the first conveying member 26 has a larger diameter than the aperture defined
in the second
conveying member 27.
Figure 4 shows the vibratory conveyor 21 of the first embodiment in operation.
Here, an
edge of the operative end 25b of the first conveying member 26 is arranged to
be level with an
edge of the inlet 17. When the air is sucked in through the inlet, air is
drawn in through the
gap between the bottom surface 12a and the first conveying member 26. This air
disturbs the
mixture of materials, which are fed onto the vibratory conveyor 21 from a feed
conveyor 24. At
a point at which the air is drawn into the inlet, i.e. at the edge of the
inlet, the low density
material is sucked into the suction duct 11. At the same time as the low
density material is
drawn into the suction duct, the high density material falls due to gravity
from the conveyor
onto the second conveying member 27. The low density material is then
channelled through
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the suction duct 12 into a discharge duct. The discharge duct channels the low
density
material to a first collection point. Meanwhile, the high density material
falls due to gravity
through the aperture in the second conveyor into a second collection point.
In use, air is also drawn in through the gap between the first conveying
member 26 and
the second conveying member 27, and through the aperture defined in the second
conveying
member. In this way a plurality of air channels feed air into the inlet,
creating an even or
laminar airflow at the operative end 25a which separates the low density
material from the high
density materials.
In the embodiment shown in Figures 3 and 4 the first conveying member 26 is
not
connected to the second conveying member 27, and the members 26, 27 vibrate
independently. However, it should be understood that the conveying members 26,
27 can also
be connected to vibrate in unison.
Figure 5 and 6 show a second embodiment of a separation apparatus 2 in which
the
material separator 10 described above is used to suck low density material in
through the inlet
17. In the second embodiment the conveyor is vibratory conveyor 31. However,
in contrast to
the first embodiment, the conveyor 31 is quadrilateral in shape, for example
rectangular. The
operation and features of the conveyor 31 are substantially the same as those
described for
the first embodiment. The differences between the conveyor 21 and the conveyor
31 will now
be described.
In the second embodiment the vibratory conveyor comprises a plurality of
separate
vibratory conveyors. Each one of the plurality of separate vibratory conveyors
31 has a first
conveying member 32 arranged above a second conveying member 33. Both of the
first and
second conveying members have an operative end 34, which is arranged adjacent
the inlet 17,
in use.
The operative end 34a of the first conveying member 32 has an edge 37 which
has a
first region 38 either side of which are second regions 35. The first region
38 is arced and
defines a semi-circular edge which corresponds in shape and dimension to the
edge of the
inlet 17. In the second region 35, the edge is angled away from edge of the
first region 38.
In the first conveying member 32, a wall stands up from the floor 36 around
its edge. No
wall is provided in the first region 38. In use, the walls in the second
region 35 act like a chute
to channel the mixture of materials to the operative end.
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In use, the low density material is sucked from the operative end 34a at or in
the vicinity
of the first region 38. The high density material falls due to gravity onto
the second conveying
member 33. The second conveying member 33 also has a first region and a second
region in
which an edge 34b is a straight edge in the first region in a line from the
end of one second
5 region to the other. As with the first conveyor, the edge of the second
region is angled away
from the edge of the first region.
In the second conveying member a wall can optionally be provided.
10 The first and second embodiments described above feature an arrangement in
which air
flow is induced between the first and second conveying members 26 & 27 and 32
& 33 by the
suction effect created by the air moving part 10. This air flow aids the
separation effect of the
separation apparatus.
In a further embodiment of the separation apparatus (not shown), a vibratory
conveyor
as shown in Figure 7 is used. The vibratory conveyor is substantially the same
as those
described for the separation apparatus of the first and second embodiments. In
this further
embodiment, those vibratory conveyors are supplemented by providing a first
and second
sidewall 50, 51 to connect a first conveying member 52 to a second conveying
member 53.
The sidewalls 50, 51 are provided to define a walled channel having a first
end and a second
end 54, 55.
In use, a fan blower is arranged to blow air into the first end. The fan
blower forces air
to move through the channel from the first end 54 to the second end 55. The
air exits from the
second end 55 through a slit 56. In use, the second end is arranged in the
vicinity of the inlet
17. Upon exiting the second end, the forced air acts upon the low density and
high density
material in the vicinity of the inlet 17 to supplement the separating effect
of the air moving
apparatus 10. That is, the air leaving the slit 56 imparts an upward vertical
component of force
to the low density material to aid the separation effect.
Figures 8-10 show a third embodiment of a separation apparatus 3 in which the
material
separator 10 described above is used to suck low density material in through
the inlet 17. In
the third embodiment the conveyor is an endless conveyor 41. The operation of
the
separation apparatus is the same as described for the first embodiment, except
the second
and third air channels of the first embodiment are not present due to the
vibratory conveyor
consisting of one level.
In use, the endless conveyor is supplied with a mixture of materials, which
are
transported at a predetermined speed to the material separator 10. As the
mixture of materials
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nears the inlet 17 the materials are disturbed. When the materials are at, or
are in close
vicinity to, the inlet 17, the low density materials are lifted from the
conveyor and sucked into
the suction duct 12 leaving the high density materials on the conveyor.
Subsequently, the low
density materials are channelled to a first collection point and the high
density materials are
channelled to a second collection point.
As shown in Figures 8 and 9 the endless conveyor processes discrete containers
42,
which contain the mixture of materials. However, it should be understood that
the endless
conveyor can have sidewalls and process a continuous stream containing a
mixture of
materials.
The conveyor has a continuous a web of material which allows air to be drawn
through
the conveyor 41 to create a second air channel to increase the evenness or
laminar nature of
the air flowing into the inlet 17. However, it should be understood the
endless conveyor can
comprise a solid belt.
The endless conveyor may also be a vibratory conveyor in addition.
Although a few preferred embodiments have been shown and described, it will be
appreciated by those skilled in the art that various changes and modifications
might be made
without departing from the scope of the invention, as defined in the appended
claims.
Attention is directed to all papers and documents which are filed concurrently
with or
previous to this specification in connection with this application and which
are open to public
inspection with this specification, and the contents of all such papers and
documents are
incorporated herein by reference.
All of the features disclosed in this specification (including any
accompanying claims,
abstract and drawings), and/or all of the steps of any method or process so
disclosed, may be
combined in any combination, except combinations where at least some of such
features
and/or steps are mutually exclusive.
Each feature disclosed in this specification (including any accompanying
claims,
abstract and drawings) may be replaced by alternative features serving the
same, equivalent
or similar purpose, unless expressly stated otherwise. Thus, unless expressly
stated
otherwise, each feature disclosed is one example only of a generic series of
equivalent or
similar features.
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The invention is not restricted to the details of the foregoing embodiment(s).
The
invention extends to any novel one, or any novel combination, of the features
disclosed in this
specification (including any accompanying claims, abstract and drawings), or
to any novel one,
or any novel combination, of the steps of any method or process so disclosed.
